Problems with British wartime high power piston engines

[robunos]

We could read our own discussion group posts too!

C'mon... that was four years ago, had a kip since then............. ;D
I'd forgotten about that topic...

I agree, to stand any chance, the P.24 needed to be developed by one of the 'big boys', but somehow, I can't see that happening.
Thanks for the information on the Merlin H, that's new to me, did it progress any farther than drawings? Or was it just a paper design to counter the P.24 should any further interest be shown?

He designed the Prince, a V-12 of 26 litre capacity to compete with the Kestrel.

Now I've read, I think in 'Aeroplane Monthly', that the Kestrel was RR's response to the Fairey Felix, a licence-built Curtiss D-12, so here we have things coming full-circle...
before we leave the subject, and just for information, does anyone have an image of the Prince, as I've never seen one?

Re. the chart above; now this is what I was getting at in my original post. The help RR and Bristol give Napier gives the historical Sabre timeline. If Bristol and RR are in from the start, Sabre milestones come 6 months sooner. But this means effort and rescources diverted away from RR and Bristol's own projects. If, however, the Sabre is abandoned early, and these rescources are available to RR and Bristol, are their own engines, and particularly the Centaurus, earlier in reaching their respective milestones? I have to say IMO, RR were right to drop the Exe and Crecy, particularly the latter.

cheers,
Robin.

 

[tartle]

Robunos... yes the HmmmMerlin was just a 1940 paper exercise.. would have been built very quickly as it used Merlin 61 components where possible... the drawing is from Lyndon Jones RRHT book of cutaways. The Fairey Felix was just the name for the Curtiss D-12, which Fairey intended to licence-build in Britain but never did. He did import 50 engines though. The D-12 looked like pic below.
Forsyth used the valve gear on the Prince and P24.

 

[tartle]

One of the aero engine research methods I use is to find out about an engine and then discover what it powered; research the aircraft and find information about the engine to inform the next cycle of research. Recently one such cycle of researching the Merlin 2-stge supercharger engines led me into our local OXFAM bookshop where I discovered a copy of "A Most Secret Place" by Johnson and Hefferman. This covers an interesting selection of A&AEE reports written by test pilots at Boscombe Down 1939-45; the second author flew on some of the original flights that generated the information for the reports...hair-raising!
The High altitude Wimpey and its Merlin 60 was what I was after and it was a revelation to flesh out the meaning of comments in the Fedden and Hooker stories...... but I was also intrigued to discover the reports on Martin Baker's fighter prototypes.
Martin’s Aircraft Works’ was founded by Sir James Martin as an aircraft manufacturer in 1934. The factory was established in 1929 and four aircraft prototypes were produced: MB1, MB2, MB3 and MB5. It was during the designing and testing of the MB1 where James Martin and Captain Valentine Baker started their friendship and ‘Martin-Baker Aircraft Company Ltd’ was established.
The MB3 fighter is of interest here as it was originally proposed with a Griffon but , under pressure from the Ministry, was fitted with a Sabre. After the MB1 a spec F.18/39 was drawn up to cover an MB proposal. Requirements included max level speed not less than 400 mph at 15,000 ft; service ceiling 35,000ft; AUW not to exceed 12,000 lb; armament 6 20-mm cannon. Order signed in summer 1939.
War priorities meant prototype not ready until Aug 1942 and it first flew on Aug 31st. On 12th September 1942, during a test flight of the Martin-Baker MB3 prototype, Captain Valentine Baker was tragically killed. The engine seized and he was forced to make an emergency landing, during which the aircraft struck a tree stump. Captain Valentine Baker's death greatly affected Sir James Martin, so much so that pilot safety became Martin's primary focus. The Sabre had suffered a failure of one of the cranks driving the movement of the sleeve valve.
The MB5 was an MB3 development with a Griffon. It flew on 23rd May 1944 and after a mod to the tail to improve directional stability was found to have superb handling. Its 2,350bhp Griffon conferred at top speed of 460 mph at 20,000ft possibly the fastest single-engined piston fighter at that time.
Ill luck again? The Griffon failed on take-off at a Farnboro' postwar display... but this time it was landed safely.
So what if MB had been given authority to push through development at haste, then it is possible the MB3 or MB5 could have been in production at the end of 1942...hmmm

 

[alertken]

Why no resources into MB5? The officlal mind was informed by wisdom that RAE+scientists (graduates) did Pure, industry (engineers, ex-apprentices) did Applied Research. So Eureka! novelty in State-funded labs, Product Definition and Production in firms. This all speaks to British class structure, and to a 1917 decision to confine Farnborough to Experiment. So, with scarce business, only 1920s' Ring of firms was admitted by Air Ministry to tender for R&D. Not enough work even for them. So, as 1930s unfold...no succour for Fairey-in-engines (original, or Curtiss-licence), or Wolseley (original, or Pratt-licence), or General (Hispano-licence). Don't need them/can't employ who we have already. Airspeed slithered in with (to be) Oxford off a PV civil type requiring no R&D.

When Minister Swinton in 1936 caused SBAC to endure "sub-contracting" (licenced second-source, supervised by Design Parent) he found himself obliged to concede the point that resultant hi-volume production experience must not create Post-War design competitors. So, few, very few design tenders were considered, 1938-44 from new entrants like Heston, Folland, Cunliffe-Owen...and MBA. The only exception, by Cripps, arose from the need to berth WEW Petter+his jet bomber notion. Craven/Vickers had only grumpily tolerated Westland as second-source Spitfire/Design Authority Seafire (and, later, small-Merlin-Mark Spitfires) because their owner, John Brown, was a fellow-mariner with whom he could resolve future competition issues. Petter kept on bidding against Vickers, 1941-44, and a jet bomber was a bridge too far, so he had to go. Cripps sent Petter up North to bring English Electric back into Aero R&D in direct contravention of Swinton's deal. All this is why those Folland fighter-types got nowhere, and neither did MBA's.

It's also why Power Jets could not become a Design+Production Authority. Me, too, would yell Tom and Dick and Harry Civilian Repair Organisation Mod. Centres like Marshall's, Field's: modest Post-War business would have been a cat-fight of incomers v.incumbents. All too hard.

 

[tartle]

The necessary technologies (skills.methods, techniques) are usually underestimated... the IMechE did research that showed on complex projects that project estimate time 't' was out by Pi squared if neither the team or leader had done a project all the way through (i.e. a factor of ten); if the leader had done one before but team had not the multiply 't' by pi (around 3); if the leader and team had done similar just before then multiply 't' by pi/2 ....i.e.40% longer!
This may also account for reluctance.....

 

[Johnbr]

Cutaway of the RR Crecy II.

 

[tartle]

I assume this is the drawing in RRHT's 'sectioned drawings of piston aero engines' which published Lyndon Jones exceptional work from original detail drawings... he was, as I've written somewhere else, a technical illustrator in, I believe Dunwell's Engineering Technical Illustration Department at RR Derby... these drawings were 'foreigners' done out of his interest. The book is worth buying... I must... but the list is so long.

 

[J.A.W.]

Camm's remarks about the political aspects of successful aircraft must surely also apply to engines.

There are various authors on the subject who remark on the chicanery/undermining that went on
between makers - even in the dire need of wartime exigency.

The case of the Napier Sabre is illustrative, with R-R/Bristol (& Rotol ) apparently cited as being on
record in attempting to have it cancelled - in favour of their products.

That Napier had serious issues with making a satisfactory mil-spec production item is beyond question,
but so is the fact of the Sabre's design being an 'apotheosis' (as Len Setright termed it) of the reciprocating
fighter mill, in specific output & combat performance terms.

As the sole example of a liquid cooled 24 cylinder 'hyper' aero-engine to make its mark in combat during
WW II the Sabre is quite remarkable too.

As for a Sabre flying again, I put the question to Mike Nixon, the U.S. warbird engine man of Reno race fame,
& he reckoned that it was quite straightforwardly feasible, & that the 'complexity' of legend was, traditional British
'nuts & bolts' constructional style aside, not as difficult as is commonly imagined.

Kermit Weeks - over to you, unless Richard Branson & Peter Jackson want to do a Nile Expedition to Khartoum
& lift out those unused greased/crated Sabres dumped off the jetty after the completion of Tempest F6
tropical type-testing back in the day..

 

[tartle]

I think we have said elsewhere that the issue with the Sabre was development timescales of a new engine versus the number of engineers at Napier that had the expertise to solve the problem.. also the strength of management team to resist production of engine too early.... Hives resisted the development of the Griffon to enable his team to concentrate on the Merlin; the same goes for Vulture. In 1940 the time and space needed to solve Vulture engineering problems (which were solvable) was not available; to complicate the issue the Manchester was a heavier aircraft than the 1936 target so a more powerful Vulture was necessary for performance..making the cooling issue even worse (bad design of nacelle by Avro so a big redesign there) the right decision was made to go Lancaster with Beaufighter power eggs.
Remember that RR/Bristol were having to devote lots of energy to service issues and now Ministry wanted them to analyse Napier's Sabre problems and help there.. Bristol had issues with Centaurus and so they were keen on clarity from Ministry which meant concentrating on their own stuff.

 

[J.A.W.]

Indeed, mention of problematic Vulture issues in Manchester service use bring to the fore
the fundamental differences in flying/engine requirements between fighter & bomber/transport roles.

The Vulture powering the Hawker Tornado prototypes evidently did not hammer itself to destruction
- unlike those consigned to drudge duty in the Manchester.

The incorporation of a coordinated engine/prop management system for enabling fighter pilots to
focus on combat flying rather than faffing about fettling myriad controls - which were properly the
province of a dedicated flight engineer - is another often over-looked feature of effective European fighter
aircraft, even radials ( BMW with 'Kommandogerat' & later Bristols too).

Certainly the U.S. pilots who flew the Merlin Mustangs appreciated the automation advantages by comparison to
their home-grown machines with their numerous settings of revs/boost/mixture/prop/turbo/cooling flaps & etc needing to be juggled - esp' at times when concentrating on combat flying manoeuvres was of paramount importance.

A number of fighter pilots comment in their memoirs on the various attributes of the engines they operated
with frank candour, & in the main, do present like motor racers - in as much as they appreciate the
power/speed advantages & ability to take high power settings - without wilting - for as long as needful,
to beat the opposition.

Obviously the aircrew flying Atlantic patrols for many hours out over the ocean would have different priorities,
'cept for their mills to keep on turning, obviously.

As for the poor bloody blokes in vulnerable bombers lumbering painfully slowly over 'Festung Europa',
- how many would have lived out useful lives if the likes of the proposed Sabre powered high speed
cruise 'Super Mosquito' or Hawker high speed bomber designs had made large-scale service instead ?

 

[tartle]

There is a fascinating story to be told about the 'hammering' that the RR Griffons received in the Shackleton 1945-90. A very different operating requirement to that of a later-mark Spitfire.

 

[J.A.W.]

Please do tell, when able, T..

I always wondered how R-R wangled that Shackleton gig for the Griffon too..
Was it a contra-deal with Bristol getting the Centaurus in the Sea Fury?

Since the Griffon was originally built to a Fleet Air Arm requirement, & the Centaurus was famed
for its long ( 3,000hr, according to Len Setright) TBO, it seems they got them around the
wrong-way..

If the many decades long Shackleton operational service life had always been envisioned by H.M. Govt,
then mayhaps the Napier Nomad could have got to really prove itself - on a cost/benefit basis too?

& surely, the hammering dealt out to Griffon crankshaft bearings by Spitfires running on +25lbs boost
for anti-Diver V1 chasing duty in mid `44 - ought to have provided a harbinger of potential 'ropy' bottom
end issues?

What were Griffon TBOs?
Did the MOD stipulate a target TBO for Shackleton service contracts?
Was it a nice little earner for R-R, or simply an annoying distraction from pressing turbine matters?

Thanks in advance - for any gen forthcoming on these questions..

 

[J.A.W.]

Here's a bit about the Chrysler Hemi V16 aircraft engine, by way of comparison/possible technical interest.

http://www.allpar.com/mopar/hemi-aircraft.html

IMO - they'd have been better-off taking up Beaverbrook's offer to do the Sabre instead,
akin to what Ford (UK/GB) & Packard did with the Merlin.

Ford (USA) did do some interesting aero-engine stuff too, but that ended up truncated for use in a tank..

 

[tartle]

It is fascinating how various parts of Ford reacted to the war.
We know Ford built a huge factory to produce Merlins at Trafford, Manchester, UK working closely with RR Derby to understand every critical part and how to mass-produce them... which meant every drawing was redone to tighten up tolerances where necessary for Ford's processes to ensure interchangeability, etc,etc.
Ford France were to be the producer for French government...9e.g. for Dewoitine D520) ...fortunately nothing had got under way during first six months of 1940!
Ford USA were very 'iffy':
In June 1940, Henry Ford had offered to manufacture 1,000 aircraft a day if the government would let him do it his way, and during a discussion with Secretary of the Treasury regarding what the Ford company might produce, Ford's son Edsel tentatively agreed to make 6,000 Rolls-Royce liquid-cooled engines for Great Britain and 3,000 for the U.S. RR supplied a complete set of drawings of Merlin XX and Ford set about redrawing them for production. However, at the beginning of July, Henry Ford stated that he would manufacture only for defence, not for Britain, and the entire deal was declared off. Members of the Defense Advisory Commission subsequently began negotiations with other manufacturers in an effort to place the $130,000,000 Rolls-Royce order, and Packard Car Company was eventually chosen because the engine's British parent company was impressed by its high-quality engineering (also some key engineers from Derby who had been at RR's US car plant in 1920 that was eventually closed had migrated to Packard). Agreement was reached in September 1940, the drawings supplied to Ford USA were extracted and sent to Packard, and the first Packard-built engine, designated V-1650-1, ran in August 1941. Packard were first into production with the Merlin 60 series with the two-piece head. Sometimes it is stated that the head was specially designed for Packard... it wasn't. Production logistics meant it was easier to incorporate into ptoduction in USA so they were first to produce it.

 

[tartle]

The key engineer to facilitate US Merlin production was Maurice Olley who was the man that made Cadillacs smooth ride!
'A fundamental engineer'
"Olley was what I call a fundamental engineer, as opposed to a higher-profile guy like [Chevrolet chief engineer] Ed Cole," Walters said. "Cole was an engineer, too, but took credit as an executive for a lot of other people's work. He was able to sell large programs to boards of directors and such that Olley couldn't do."
Olley was born June 12, 1889, in Scarborough, England, attended the Birmingham Technical School and the University of Manchester in England. He was a tool designer for H.W. Ward & Co. in Birmingham and was with Rolls-Royce from 1912 to 1917 as a designer on the personal staff of Sir Frederick Henry Royce.
"In that capacity, he was one of the three developers of the first Rolls-Royce aircraft engines," Walters said. "They were water-cooled eight-cylinder inline engines."
Olley moved to the United States in 1917 to take charge of aircraft engine production for Rolls-Royce in New York and Cleveland. He reported directly to Royce. "No drawing was ever approved unless Royce approved it himself with a big script 'R' on it," Walters said.[Olley also designed the reduction gearbox used on some versions of Liberty engine]

Olley was promoted to chief engineer for Rolls-Royce in America in Springfield, Mass.
In 1930, Olley joined Cadillac in Detroit as a troubleshooting engineer. His services were so much in demand that in 1934 he was given a specially created position in GM as engineer in charge of the Product Study Department.
From 1930 to 1937, Olley was largely responsible for the design of various independent suspension systems and their introduction on GM cars. His work helped define modern ideas of automotive ride and handling.
Olley returned to Europe in 1937 as passenger vehicle engineer with Vauxhall Motors, GM's English subsidiary. He took a leave of absence in 1939 to act as U.S. engineering representative on aircraft engines for Rolls-Royce, supervising the manufacture of Rolls-Royce parts and the start of the Rolls-Royce Merlin engine production at the Packard plant in the United States.
During the final years of World War II he was an adviser to the British Ministry of Supply. After the war he returned to Vauxhall.

This is the standard history but it is worth reading this to get two sides to the story of Merlin production in USA. I think the truth is lost in the mists of time but one can get a reasonably accurate story from devining these two!

 

[J.A.W.]

Yeah T, I've heard that ol' Henry & Adolf were into mutual admiration..
& like ol' Joe Kennedy, father of J.F.K. ( but unlike Adolf, ironically), he was an old school Anglo-phobe..

Still, as an autocrat, Ford could largely do want he wanted - with his stuff - in the USA.

Thanks for the link, but I'd reckon though - the proof is in the pudding, as it were, aero-engine-wise,
& Ford (USA) did build thousands of aero-engines in WW 2, but they were P&W R-2800s,
- not their in-house 'Merlin-beater'..

 

[alertken]

T: many tks for this. Revisionist received wisdom is that Henry Ford, with other US businessmen, 1938-ish, was for strong European leaders, anti-Bolshevism. Not that he wanted UK to fall to fascism, but he wanted UK to stop distracting Men of Steel from the job of toppling Stalin. So: no US Ford munitions for UK.

The logic of this is that Ford/France and Ford/UK became involved in Merlins, insubordinate, and despite Henry. Your links now introduce Henry's preference not to batter Britain but to beat Merlin by building a better engine...for any Customer Approved by his Govt.

Surely that is right. I cannot accept that Ford/UK could have happily thwarted Henry by aiding a Govt. of whose Policy he disapproved.I prefer the reading that, rather than footle with alien drawings, to fit Merlin for scientific production, it would be quicker, cheaper to bring his own product onstream. Good luck to Packard... while you are bogged down, I'll be steaming ahead.

 

[tartle]

Politics of the time probably meant the PR (aka our PM's earlier job... ah that explains a lot) dictated how the situation was presented. Also can you imagine what RR people would have said if they had to take on the Ford! Royce was so offended at the Renault and RAF engines in WW1 that he went against the commercial factions in RR who wanted just to keep factory busy (not making much from cars in a war! not till they armoured them!) and the Eagle/Falcon/Hawk were born and were made in quantities exceeding any other UK design.
And Henry Ford would have a good idea that taking on a British inch thread machine could be a nightmare ...no would be a nightmare! Commonality would dictate that change. Incidentally the Eagle 22 was a What-if engine... what-if we have another round of piston engined aircraft before the jets take over? What-if Napier never get their development act together? etc.
Maybe Henry realised USA would get dragged into war and so the resources of Ford were better kept to meet the needs of a domestic customer rather than a foreign one with the Atlantic to slow communication. I remember the revelation of getting a drawing through to Indianapolis from Derby in 1977 that took 4 hours to FAX, in pieces, so much faster than the post, or jumping on an aeroplane.
P.S. eventually we ( a group gathered round a millionaire collector of engineering.. hear the Merlin roar) will restore a Sabre we have in the cupboard!

 

[JFC Fuller]

The Ford GAA V12 aero-engine has its own thread here: http://www.secretprojects.co.uk/forum/index.php?topic=5494.0

It apparently achieved 1,800 hp on the bench, could have made for an interesting engine for the P-51.

 

[tartle]

stuff here

 

[tartle]

Pugh's 3 volume work on RR gives this Ford>Packard explanation.

 

[J.A.W.]

Interesting, thanks, T..

Not too many DOHC aero-engines built, ( Lion, Jumo 211, AM 38),
& valve gear issues being a significant factor in hot-rod Merlin Reno racers.

Exciting news about the pending Sabre restoration,
- is that pic of a crashed Sabre unit with a bent prop shaft?
Or is it a distortion in the photo?

I note that a (partial) Sabre overhaul special tools kit was recently being offered
on the Hawker Tempest Page site, if of interest..

 

[Kevin Renner]

Ford's not quite still born V-1650 in a cutaway reveils its auto motive origins. The side by side connecting rods for one. But Ford would of also used steel csstings in place of forgings as Ford pretty much led the world in the technology at that time. But the time frame that would be needed to bring the engine into service made it a non-starter IMO.

I sometimes wonder if the RAF and would of been better served if Napier had built license built R-2800s. As wonderful of an engine as the Sabre was for a nation at war there is another factor involved. I wonder just what the total man hours were in the production of each

 

[J.A.W.]

Link to Sabre service tools.

http://www.hawkertempest.se/sabreservicetools.htm


R-2800 vs Sabre?

Well - how many V1 cruise-missiles did R-2800 powered aircraft intercept?

The hi-po P-47M was ostensibly cobbled up to be a V1 catcher, but was both too late & too slow..

A few Sabre Tempest units stopped 800+ V1s from killing Londoners in `44..

Radials have their place, in bombtruck/transporters, but as fighter power, they are not a match
for thoroughbred in-lines.

Too thirsty/draggy & prone to wilt at extended high power settings.

Like Grand-Prix racers, fighter jocks want the most powerful, responsive, hard running engines
to power their machines to victory..

Hawker Fury article from 'Flight' (& note Sabre in-line power performance beat radial Centaurus performance).

http://www.wwiiaircraftperformance.org/Fury/Sea_Fury_Flight.pdf

 

[J.A.W.]

Sabre full tool kit laid out, - only 'bout a thousand items..

http://www.enginehistory.org/members/articles/NapierSabre/Tools/index.html

 

[robunos]

Ford's not quite still born V-1650 in a cutaway reveils its auto motive origins. The side by side connecting rods for one. But Ford would of also used steel castings in place of forgings as Ford pretty much led the world in the technology at that time.

I think reliability would have been a strong point with this engine, good for bomber applications, but I wonder about it's development potential, for fighters...

I sometimes wonder if the RAF would of been better served if Napier had built license built R-2800s.

Which brings us (almost) neatly back to the start of this thread... ;D

cheers,
Robin.

 

[J.A.W.]

& Robin, if going by the relevant available data, the answer to the case in point - is a resounding no..

The RAF had R-2800 powered aircraft on strength, but used few of them in hot combat roles in the ETO,
the most intense, technologically demanding theatre in the WW 2 air-war.

& when they did, like the infamous suicidal Ventura daylight raid on the Phillips works, it was V.C.-time.

The RAF had P-47s, which the RAF deemed as suitable for operations against the lesser forces of Nippon,
but assuredly not a match for their Sabre powered Hawkers in either A2G or A2A roles in the 2nd TAF,
or as ADGB defence assets..

Even the Soviets, who received ~200 P-47s under Lend-Lease, found the idea of using the turbo-
boosted, high-altitude developed Thunderbolt - for low-level tactical A2G/A2A ops as ludicrous..

I do wonder if they ever used them post-war in attempts to catch the snooping PRU 19 Spitfires
flying high & fast over the 'Iron Curtain'?

The RAF was certainly embarrassed that its own new-fangled Meteor jets could not run intercept
vectors successfully on those recce Spits either..

 

[J.A.W.]

A brace of Hawker Furies, showing the contrast between Centaurus & Sabre installations..

http://www.aafo.com/hangartalk/showthread.php?2812-Hawker-Fury-Prototypes-3-amp-4& p=110375#post110375

 

[tartle]

To put the challenge of Napier's problems into context this is a chart I have drawn up from a status report for Typhoon 17 dec 1943!

 

[J.A.W.]

& yet the Typhoon squadrons had seen off the FW190 fighter-bombers earlier in `43,
- hunting them down relentlessly - like coursing hares - as they fled back to France while frantically pumping
high-test C3 juice into their superchargers as ADI - in a vain attempt to stop their air-cooled BMW radials
from wilting at max boost..

Something the then available Spits ( or unavailable Tornados) could not do..

Indeed, the sorry debacle that was Sabre production is a blot on the copy-book of British mid-war schemes.

However, they did get good enough to run rat-catching of Me 262s in `45, once Rotol had been tuned up
enough to provide props capable of handling higher boost/powered Sabres..

& right up to the mid-50s there were enough functional Sabres still on hand to provide for TT Tempests to
lead Meteors & Vampires a merry dance - in air-to-air gunnery training..

To bad the fools then scrapped the bloody lot..

 

[Basil]

J.A.W.,
exhaust thrust stubs do no help in cylinder scavenging - in contrary, they add additional work to the piston to expel the spent gases through the nozzle. To get a scavenging effect you have to combine different exhaust headers (depending on the firing order) so that the vacuum left by the preceding pulse helps to expel the following pulse (as a nice example see the "bundle of snakes" headers of a Ford GT 40).
You are right, the rod construction of a radial with its master rod and slave rods is not too elegant with all its problems of uneven firing, vibration and other engineering challenges. It's a pity the different patents for true motion connecting rods (especially by Curtiss Wright in the 1940s) did not realize into hardware.
I do not agree that radials are not suited for very fast propeller aircraft - many of the fastest piston aircrafts had radials installed; also see Reno. Besides, the hot cooling air from radials was used to get additional thrust which works even better at high speed (as it was done with the radiator heat of liquid cooled engines). I know of a net thrust calculation of the stillborn BMW 802 - the thrust from hot cooling air did by far exceed the cooling drag of the engine and power consumption of the cooling fan (BMW was supplying total power packages to airframe manufacturers, not just the bare engines). Of course radials normally have a slightly higher fuel consumption because of cylinder head temperature regulation.

 

[JFC Fuller]

XP-47J, XP-72, Tempest II, Fury/Sea Fury, all achieved impressive performances on radials. The Sabre was outstanding at low to medium altitude in Europe and certainly hung around for years after the war.

 

[Basil]

Sorry, I placed my input in the wrong thread (was intended for "Increasing the Charge"). Admin, would you please remove it from here? Thank you.

 

[J.A.W.]

XP-47J, XP-72, Tempest II, Fury/Sea Fury, all achieved impressive performances on radials. The Sabre was outstanding at low to medium altitude in Europe and certainly hung around for years after the war.

JFC F, That (seemingly mythical) '500mph' prototype Thunderbolt performance is oft repeated, but have you
(or anyone) ever seen any actual tests that verified it?

& I mean 'Boscombe Down' type by the USAAF Air Materiel Command, not possibly spurious manufacturers
'fudged' figure 'estimated' performance..

There is no doubt that by sheer mass the big radials could shift well designed fighter air-frames along
smartly ( viz F4U/F7F/F8F types also) if in short, heat rejection limited bursts , but that did not mean they were ideal for the task, when compared feature for feature with in-line rivals.

For example, the late production P-47N became a virtual flying 'gas-tank' - wet wing
'n' all - to feed its thirsty turbo R-2800, that it got so heavy as to require nearly a miles worth of
take off run, & was at dire risk of becoming a rolling crematorium if lift off did not occur..

& when you look at the max continuous cruise listed in aircraft data sheets, the R-2800 powered fighters
make ~100mph less than what a Merlin Mustang or Sabre Tempest could comfortably accommodate.

 

[J.A.W.]

See here..

http://www.wwiiaircraftperformance.org/f4u/corsair-II-III-ads-b.jpg

http://www.wwiiaircraftperformance.org/p-47/P-47_thunderbolt2-aircraftdatasheet.jpg

http://www.wwiiaircraftperformance.org/tempest/tempest-v-ads-sabre-IIb.jpg

http://www.wwiiaircraftperformance.org/mustang/mustang-IV-ads.jpg

 

[J.A.W.]

A Kiwi Tempest pilot on 'Rat-catching' anti-Me 262 duties, Ron Dennis ( together with his wingman),
ran the Tempest WFO for 50 miles in hot pursuit of such a German jet & shot it down, when the Jumo
turbines cried 'enough' 1st..

He was quoted re the Sabre Tempest,

"The engine loved tough handling & never objected to maximum revs or boost for extended periods."

When Rotol props finally appeared ( something Camm was reportedly pissed-off about) the Tempest was
cleared for +13lbs boost/3850rpm settings, something Ron Dennis liked, since he reckoned the
earlier De Havilland props were prone to blade shedding when run hard at the Sabre's higher powers..

 

[J.A.W.]

Notwithstanding all the production dramas, service difficulties & associated costs,
Sabre power did enable the air-superiority Tempests of the 2nd TAF to bag every example of the
Nazi wunderwaffen turbine-powered & long-nosed/hi-po piston engined LW types in service in `44-45.

RNZAF top scoring ace Evan Mackie really liked the Tempest, rating it over both Spitfire & Meteor types that
were available to him in the final months of the conflict, as 2nd TAF Wingco Flying..

He reckoned..

"The harder they were flown, the better they went...they could be thrown around the sky like a piece of paper."

 

[tartle]

1944-45 was the period in which reliability of Sabre increased massively; the overhaul life was still low but at least you knew it was not going to fail you. It still consumed many man-hours to manufacture and spares demand was obviously higher but it had its place in the mix of things. Still was extremely useful as a ground attack vehicle although rockets projectiles were not that accurate they were psychologically effective..... but that is another thread...
Nan-hours because it needed nursing like a one-year old which is more or less what it was in development terms.

 

[J.A.W.]

AFAIK, although cleared to use them, Tempests never did fire RPs in anger in WW2..

Typhoons however - did fire off more than 200,000.
- If any doubt the effectiveness of RPs, just look up the unfortunate 'Friendly Fire' incidents that featured them..
Viz, Johnny Baldwin's wing led decimation of RN minesweepers in the channel....or the 'Cap Arcona'..

& again,much like Grand-Prix racers, I doubt that fighter pilots cared much what TBOs amounted to..

Larry Bell worked out a deal with GM to over-boost the Allison mills in his P-39s even at a cost of 40hr TBOs,
- on behalf of the VVS - for the Russian Front..

 

[J.A.W.]

1944-45 was the period in which reliability of Sabre increased massively; the overhaul life was still low but at least you knew it was not going to fail you. It still consumed many nan-hours to manufacture and spares demand was obviously higher but it had its place in the mix of things. Still was extremely useful as a ground attack vehicle although rockets projectiles were not that accurate they were psychologically effective..... but that is another thread

'Nan-hours' T?
No wonder they had trouble getting Sabre production satisfactorily sorted,
if those 'nans'.. had more'n likely wanted to..
..hive off & feed the bloody cat, make the old mans tea, or some such powder-taking type activity..

Mind you,

R. Beamont wrote that he'd got a right bollocking - for being openly critical of Hawker workers ethics
when they went on strike, - just as Tempests were badly needed for anti-V1 defence duties..

Something neither Henry Ford or uncle Joe would've been too cool about, nor Todt/Speer like-wise..